Increased prices of conventional heating fuels and predicted shortages have prompted the adoption of electric heating in many homes. Since the energy to heat a house exceeds the electrical energy normally supplied to the home in many areas of North America, total conversion to electric heat would necessitate tremendous increases in the electrical generating and transmission capacity of the utility companies. This situation can be alleviated by the use of off-peak electricity and heat storage for home heating, but units suited to the extreme North American requirements do not exist. The inventors have invented an efficient off-peak, electrical central air heating system for buildings that uses heat that is generated electrically during the off-peak power periods and stores the generated heat in a heat storage material for use during the peak power periods.